A killer has just been dragged screaming to the electric chair, and after his execution the doctor - Warren Chapin (Vincent Price) - performing the autopsy on his body finds a curious physical phenomenon. As he muses it over, a relative of the deceased enters the examination room and introduces himself as Ollie Higgins (Philip Coolidge), explaining he has a pass which allows him access to the body. Chapin reluctantly lets him stay, but grows so carried away by the theories racing through his mind that he tells all to him: the killer's spine had been broken in two, so what, Chapin posits, if there were some creature which thrived on fear that had caused such an effect?
What indeed, and it was William Castle who thought of it first, or his regular screenwriter Robb White did at any rate. The film doesn't actually start like that at all, for the first thing you see is the director himself, announcing that there are some people in the audience who are more susceptible to the consequences of terror than others, so whatever you do you must scream if you wish to survive. All of this was the set up for the filmmaker's latest gimmick, Percepto, where the equivalent of palm buzzers were fitted to selected seats to give viewers a shock and with any luck make them cry out, thus prompting the rest of the audience to do the same.
If ever there was a film built around its gimmick, it was this one, as the plot makes barely any sense without it, and as not too many theatres were equipped with the Percepto devices, you can only imagine what kind of reaction it provoked at the time. Cinema managers were encouraged to plant paid members of the staff in the auditorium to scream at the proper moment as well, which might have worked, although you can envisage a bunch of avid horror fans letting loose with the yelling and hollering simply for the hell of it. They probably threw popcorn at the supposed rampaging Tingler for good measure, not that the budget extended to putting one in every theatre - but what precisely was the critter?
It's all about the scream, and according to this the monster of the title was a centipede type thing of rubbery countenance which grew out of the spines of the terrified, and the only way to neutralise its potentially back-breaking damage was naturally to make as much noise as possible. This is what Chapin discovers at any rate, real life experimentation might have proven otherwise, but who cares about that, right? Actually the doctor might have dodgy motives himself, as we see him apparently trying to kill off his adulterous wife Isabel (Patricia Cutts) - but, no, it's all right, he was really trying to scare her into creating her own Tingler. Phew, for a second there we thought he was a maniac!
Well, sorry to break it to you, but there really is a maniac in this film, although they are well-hidden. No, it's not William Castle, it's one of the characters, and we twig something is up when Ollie's wife Martha (Judith Evelyn), a deaf mute who runs her own silent movie picture house, is literally frightened to death by an apparent series of halluicinations. They include a trip to the bathroom where the black and white film displays colour in parts; according to Castle he did this by filming in colour but painting everything except the blood in monochrome, although it looks more like camera trickery. While the film doesn't quite reach the heights of delirium a synopsis might suggest, as it's all presented with a strange tone of solemnity, it simply too downright nutty to be dismissed, featuring as it does a grave Price freaking out on LSD and a finale which goes some for audacity to bring the gimmick front and centre. Music by Von Dexter.